에폭시수지의 개질을 위한 아민말단 반응성 올리고머의 합성과 특성(Ⅰ)

최향희,박기주 조선대학교 생산기술연구소 1998 生産技術硏究 Vol.20 No.2

경화후 에폭시 수지(Epon828)의 파괴 특성을 증가시키기 위해 아민 말단을 갖는 반응성poly(aryl ether ketone)은 방향족 친핵성 치환반응으로 합성하였고, N'_(B)의 화학양론값을 조절하여 분자량이 다른 올리고머를 쉽게 합성하였다. 이는 원소분석, NMR, IR로 확인하였고, 분자량의 증가에 따른 올리고머의 T_(g)가 증가함을 DSC로 알수 있었다. 그리고 XRD를 통해 이 반응성 올리고머는 결정성을 가지고 있음을 알 수 있었고, tensile modulus는 1.93 GPa, 변형률은 3.2%로서 상당히 brittle한 특성을 보여주었다. In order to improve the fracture properties of commercialized epoxy resin(Epon828), the amine-terminated reactive oligomer synthesized has the chemical structure of aromatic aryl ether ketone type. The reactive oligomer was synthesized easily by two-step reaction and can be controlled in its molecular weight by a stoichiometric reaction. It's clarified by using the elemental analysis, FT-NMR, and FT-IR. WAXS pattern of the reactive oligomer shows that the olisomer has crystallinity. The tensile modulus(1.93GPa) and strain(3.2%) of the oligomer indicate that the amine-terminated reactive oligomer is so brittle

아이소소바이드/반응성 올리고머에 의한 에폭시 수지의 개질(Ⅱ)

최향희,전윤,최재곤 조선대학교 생산기술연구소 1998 生産技術硏究 Vol.20 No.2

본 연구에서는 일반적인 상용 에폭시수지를 아민 말단 반응성 올리고머와 isosorbide를 이용하여 물성 변화를 시도하였다 유연한 지방족 고리형의 isosorbide (DDS)는 열가소성 rich-phase형성에 큰 영향을 주며, isosorbide/반응성 올리고머를 도입한 열경화성 에폭시 수지는 3개의 서로 다른 몰폴러지를 보여줌을 알 수 있었다. 파괴에너지는 isosorbide 도입량 34.2%에서 3배 정도(815J/㎡) 증가하였는데, 모듈러스의 감소(△E = 0.8GPa)는 그렇게 크지 않았다. 그중 강인한 수지는 isosorbide 도입량 34.2%, 44.5%으로 열가소성 rich-phase가 연속상이고, 열경화성 rich-phase가 분산상인 상태에서 흡수된 에너지로 밝혀졌다. 또 24.9% 도입의 경우 혼합된 두 개의 연속상이 존재함을 알 수 있었으며 파괴에너지는 열경화성 연속상과 열가소성 연속상의 중간정도의 값을 보여 주었다. isosorblde/반응성 올리고머를 도입한 열경화성 에폭시 수지계의 파괴저항은 연속상 가교점 사이의 분자량과 CSIF를 관련 지워 잘 설명할 수 있음을 알 수 있었다. 각 상의 T_(g) 이하 온도에서 수지의 저장 탄성율은 flexural modulus와 비슷한 값을 보여주지만, 열경화성 rich-phase의 T_(g) 이하, 열가소성 rich-phase의 T_(g) 이상의 온도영역에서는 3개의 서로 다른 상이 관찰되었다. 결론적으로 isosorbide/반응성 올리고머를 도입한 에폭시 수지계의 파괴에너지는 충분히 높고, 적절한 탄성율로 여러 범위의 응용이 가능할 것으로 생각된다. A commercialized Epoxy resin was modified with isosorbide and amine terminated reactive oligomer. Isosorbide which has aliphatic cyclic chemical structure was found to influence on the formation of thermoplastic-rich continuous phase. It was found that interaction and phase behaviors of the thermoplastic-rich and thermoset-rich continuous phases of this resin system have influence strongly on physical properties and morphology of the resin, This resin system was shown to display three morphologically distinct states that determine their thermal and mechanical properties. A three-fold increase in the fracture energy was observed without a significant decrease in the modulus. The toughest resins have ductile energy absorbing thermoplastic-rich continuous phases with thermoset-rich inclusions 34.2% and 44.5% of isosorbide loading levels while the more brittle, lower loading level materials, 7.7% and 16.0%, had thermoset-rich continuous phases with thermoplastic-rich inclusions. The 24.9% loading level system possessed a mixed continuous phase morphology and had a fracture energy intermediate between the thermoset-rich continuous system and the thermoplastic-rich continuous phase system. Phase seperation and morphology of the resin system also were confirmed by a transmission electron microscopy and dynamic mechanical analysis. It was further demonstrated that the fracture resistance of this system could be very well modelled by relating the average molecular weight between crosslinks of the continuous phase with the critical stress intensity factor. The characterized phase mixing led to the determining of a proportional relationship between the critical stress intensity factor and the average molecular weight between crosslinks of the continuous phase. The observed proportionality between these two variables may indicate that a single fracture mechanism, depending on the molecular weight between crosslinks of the continuous phase exists This relationship, if valid, indicates that the nature of the inclusion in these reactive thermoplastic oligomer and isosorbide resin system is insignificant, and that the fracture resistance of these rosins Is determined by the nature of the continuous phase.

열공형과 비열공형 피질하 혈관성 치매에서 위험인자의 차이에 관한 비교 연구

배희준,정지향,유경호,나덕렬,김상윤,최경규,양동원,손의주,이상도,김재우,박경원,김응규,이재홍,박미영,한일우,함동석,최문성,하충건,최성혜,이애영,이병철,한설희 대한치매학회 2003 Dementia and Neurocognitive Disorders Vol.2 No.2

Backgrounds and Objectives: Vascular dementia is a group of dementing disoders arising from various stroke syndrome. Among these. subcortical ischemic vascular dementia (SIVD) is regarded as a relatively distinct clinical entity. However, MRI patterns of SIVD are not homogenous. In some patients, lacunes are dominant, and in others, subcortical white matter changes are. This study was designed to compare risk factor profiles between SIVD with and without multiple lacunes. Methods: We divided 47 subjects (22 males, mean age. 68 years) recruited from VADAPET (Multicenter Trial For Evaluation Of The Changes In the PET Images Of Subcortical Vascular Dementia Patient) study into two groups one with more than 5 lacunes in deep gray matter (lacune group) and the other with 5 or less(non-lacune group) Clinical characteristics and laboratory findings of two groups were compared. Results: Nineteen of 47 patients (40%) belonged to the lacune group. The lacune and non-lacune groups d d not differ in the following variables: age, hypertension, diabetes mellitus, hyperlipidemia heart disease, history of stroke or TIA, history of trauma or major surgery, family history of hypertension stroke, or dementia, age at diagnosis of dementia, body mass index, white blood cell count, ESR, CRP, fibrinogen, hemoglobin A1C, total cholesterol. LDL cholesterol creatinine, proteinuria, glucosuria, and microhematuria. However, male sex, smoking alcohol. hemoglobin, and HDL cholesterol were possibly associated more with lacune group SIVD than with non-lacune group (p<0 1) Multivariate analyses revealed that smoking, hemoglobin, and HDL cholesterol were independent predictors of SIVD with multiple lacunes Conclusion: Our study suggests that SIVD with multiple lacunes may be significantly different in smoking habits hemoglobin, and HDL cholesterol from SIVD without multiple lacunes.

여성의 피부관리실태와 관련요인

구재희,남철현,최연희,배향선,신옥순,양숙희,이명옥 慶山大學校 保健福祉硏究所 2002 保健福祉硏究 Vol.7 No.-

This study was conducted to analyze aspects of women's skin care and related factors in order to contribute to community residents's right skin care. The subjects of this study was 800 women who were 15 to 65 years old. Data were collected in Daegu City and Kyungsan City from June 21, 2002 to August 18, 2002. The results of this study can be summarized as follows. 1. According to socio-demographic characteristics of the respondents, 26.8% of them were in twenties. 50.9% of them was students at colleges or graduated from collges. 38.3% was students and 37.5% was housewives. 55.5% belonged to the middle economic class. 2. 47.9% of the respondents replied that they were in good health. 57.2% of them had fair skin, while 25.1% had dark skin. According to health condition of face skin, 61.5% was in regular condition, while 26.0% was in bad condition. 29.9% had drying face skin and 21.3% had neutral or complex character of face skin. 3. Among the reasons they had trouble with face skin, the proportion of having the rough skin was highest (25.0%). 16.6% replied that they had trouble with a lot of wrinkles and 16.3% replied that they had trouble with dark face skin. 25.4% responded that their face skin was too tight. 13.3% replied that they had trouble with scars. 4. The factors significantly influencing the experience of skin care were age, education level, residence, experience of side effect of cosmetics, experience of skin diseases on face or body, experience of trouble after receiving skin care, and experience of trouble with acne. From above results, it can be concluded that selection of proper skin care rooms is important in receiving desirable skin care and preventing side effect related to skin care. The women also must be cautious in selecting and using cosmetics and massage pack. The government, related organizations, and skin and beauty specialists must make efforts to develop education programs for healthy skin care.

Purs Lane의 유용성분과 아질산염 소거능 검색

김향숙,변복수,최주희,박지영 충북대학교 교육생활연구소 2001 생활과학연구논총 Vol.4 No.-

This study was carried out to examine the useful components of Purs Lane and their nitrite scavenging effect. Leaves and stems were separated and analyzed fo general chemical composition, amino acid composition, and dietary fiber contents. Anti-oxidant nutrient such as total vitamin C, total phenol ice, and vitamin E contents were also analyzed. Nitrite scavenging effects of methanol extract and aqeous extract were examined.

광릉수목원 혼합림에서 복사 에너지의 계절 변화 특성

김연희,조경숙,김현탁,엄향희,최병철 한국대기환경학회 2003 한국대기환경학회지 Vol.19 No.3

The measurement of the radiation energy, trunk temperature, leaf area index(LAI), air temperature,vapor pressure, and precipitation has been conducted under a mixed forest at Kwangneung Arboretum during the period of 2001. Characteristics of the diurnal and seasonal variation of the radiative energy were investigated. The aerodynamic roughness length was determined as about 1.6m and the mean albedo was about 0.1. The downward shortwave radiation was linearly correlated with the net radiation and its correlation coefficient was about 0.96. From this linear relation, the heating coefficient was calculated and its annual mean value was about 0.21. The albedo and heating coefficient was varied with season, surface characteristics, and meteorogical conditions. The diurnal and seasonal variations of radiation energy were discussed in terms of the surface characteristics and meteorological conditions. In the daytime, during clear skies, net raditaion was cominated by the shortwave radiation. In presence of clouds and fog, the radiation energy was diminished. At night, the net radiation was entirely dominated due to the net longwave radiation. There was no distinct diurnal variation in net radiation flux during the overcast or rainy days. The net radiation was strongest in spring and weakest in winter. The seasonal development in leaf area was also reflected in a strong seasonal pattern of the radiation energy balance. The timing, duration, and maximum leaf area and trunk temperature were found to be an important control on radiation energy budget. The trunk temperature was either equal or warmer than air temperature during most of the growing season because the canopy could absorb a substantial amount of sunlight. After autumn(after the middle of October), the trunk temperature was consistently cooler than air temperature.

폐 내 병변으로 인한 소아 급성 호흡부전의 원인 질환과 예후

이혜영,박지숙,최희라,서지현,김점수,임재영,최명범,박찬후,우향옥,윤희상 대한소아과학회 2004 小兒科 Vol.47 No.5

형질전환 제초제저항성 벼 밀양 204호의 농업적 특성

정응기,이기환,원용재,박향미,전남수,최준호,구연충,한창덕,은무영,김태산,남민희 Plant molecular biology and biotechnology research 2005 Plant molecular biology and biotechnology research Vol.2005 No.

This study was conducted to investigated the major characteristics of genetically modified rice of "Milyang 204" originated from Dongjinbyeo compared to a non-transgenic rice varieties Dongjinbyeo and Junambyeo. Basta resistant transgenic rice lines carrying bar gene produced by the Yeongnam Agricultural Research Institute were evaluated for their agronomic characters. The transgenic Japonica rice of "Milyang 204" showed inferior phenotypic traits compared to a non-transgenic rice variety Dongjinbyeo and Junambyeo. On the basis of UPOV (Union Internationale Pour la Protaection des Obtentions Vegetables) and NSMO(National Seed Management Office) the transgenic "Milyang 204" showed difference in some traits out of some agronomic traits, such as leaf color, angle of flag leaf, number of spikelets, culm length, white core and white belly compared to the nontransgenic varieties rice.

국소적 복막염으로 발현한 대나무 가지에 의한 위천공 1례

서지현,황지영,강기수,박찬후,우향옥,최명범,윤희상 대한소아과학회 2001 小兒科 Vol.44 No.7

Melanogenesis Inhibitory Compounds from Saussureae Radix

Choi, Ji-Young,Choi, Eun-Hyang,Jung, Hee-Wook,Oh, Joon-Seok,Lee, Won-Hee,Lee, Jong-Gu,Son, Jong-Keun,Kim, Young-Soo,Lee, Seung-Ho 대한약학회 2008 Archives of Pharmacal Research Vol.31 No.3

Ten compounds were isolated from the EtOAc soluble part of the MeOH extract of Saussureae Radix, with their effects on melanin production also evaluated in B-16 mouse melanoma cell lines stimulated with 3-isobutyl-1-methylxanthine (IBMX), an elevator of cellular cAMP. The compounds were identified as aplotaxene (1), 1${\beta}$-hydroxy arbusculin A (2), costunolide (3), dehydrocostuslactone (4), 11${\beta}$,13-dihydrocostunolide (5), reynosin (6), heptadec-(9Z)-enoic acid (7), ${\beta}$-sitosterol (8), linoleic acid methyl ester (9) and betulinic acid methyl ester (10). Compounds 2, 9 and 10 were identified from Saussureae Radix for the first time. Furthermore, compounds 2, 3 and 6 showed potent inhibitory effects on the IBMX-induced melanogenesis, in dose-dependent manners, with $IC_{50}$ values of 11, 3 and 2.5 ${\mu}g/mL$, respectively. As a positive control, arbutin exhibited an $IC_{50}$ value of 29 ${\mu}g/mL$.